If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.

Hmmm. That one is harder to say. Our eyes are very good at picking out patterns. So goo that we often make patterns where there aren't any. Three craters is few enough that we could just be seeing a random arrangement of craters that are close to a line. We would really need one or two more craters in the line to be sure it isn't just a fluke.

Generally, impact crater chains form straight lines. They don't meander or circle around another crater. If they do, they are not an impact crater chain.

Volcanic crater chains look very different from impact crater chains. First the craters are different; more irregularly shaped. Chains of volcanic craters can form curved lines, but if they circle the rim of another crater, they wouldn't be called a chain any more. Volcanic craters are fairly rare on the Moon, so volcanic crater chains are even less common.

Chains of pit craters, caused by collapse or subsidence of an unsupported chill crust can be less predictable, but they are not usually associated with any kind of larger crater. Pit craters are also quite rare on the Moon.

If you do find a chain of craters (impact, volcanic, or pit), you should definitely mark them, even if the individual craters are smaller than the minimum size (though it will probably be very rare for that to be the case). If a chain is very long, it may be helpful to use two or three flags to mark it.

The track from a boulder that rolled down a crater wall is a "boulder track" and not a crater chain, so it should not be marked as a crater chain.

I hope this addresses all of your questions. Do not hesitate to ask for more info if anything is unclear.